melonized gear distributor?
Thread Starter
Le Mans Master
Joined: Jul 2006
Posts: 8,117
Likes: 104
From: charlotte north carolina
melonized gear distributor?
just saw installation note on a web site for bb engines. it stated that the distributor gear must be melonized when using steel cams. can i assume all original gm distributors have melonized gears? i hate to admit it, but i never even gave the distributor gear a thought.
jeff
jeff
Melting Slicks
Joined: Aug 2006
Posts: 3,429
Likes: 20
From: Kingston Ontario
I think what they mean is it's for billet cams which are harder than stock cast cams. I don't know if GM puts out a billet cam. I have a billet cam and I can use a stock distributor gear because the cam is made with a pressed on gear softer than billet material.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
I am speaking of SBC only here ... I dunno about BBC:
Yes GM does offer billet steel roller cam ... they are OE in a lotta production motors & in GMPP motors ... I have closely inspected several ... some from later "vortec" "R" "L31" production pu motors, and also from GMPP ramjet350, ZZ4 & HT383 ... they are billet steel and do not have a pressed on gear ... & they run on a GM melonized dist gear ... melonized is what comes on dist in the vortec pu motors and on GM disti for those 3 GMPP motors. A pal recently ordered & installed GMPP roller sbc cam p/n 12370846 into ZZ4 w/ ZZ4 dist ... cam is billet steel also ... it may be mfg'd by crane. I'm Not a metallurgist ... if an sbc cam is rather smooth & shiney between the lobes I call it billet steel.
Yes GM does offer billet steel roller cam ... they are OE in a lotta production motors & in GMPP motors ... I have closely inspected several ... some from later "vortec" "R" "L31" production pu motors, and also from GMPP ramjet350, ZZ4 & HT383 ... they are billet steel and do not have a pressed on gear ... & they run on a GM melonized dist gear ... melonized is what comes on dist in the vortec pu motors and on GM disti for those 3 GMPP motors. A pal recently ordered & installed GMPP roller sbc cam p/n 12370846 into ZZ4 w/ ZZ4 dist ... cam is billet steel also ... it may be mfg'd by crane. I'm Not a metallurgist ... if an sbc cam is rather smooth & shiney between the lobes I call it billet steel.
Team Owner
Joined: Jul 2004
Posts: 40,368
Likes: 787
From: Redondo Beach, California
You can buy the melonized gears from a Chevy dealer. (Or Scoggin Dickey a forum vendor and sourse of GM parts). The part number is in the GM Performance Parts catalog. It's easy to change the gear (once you remove the distributor).
I remember looking at the melonized gear and the standard gear in bright sunlight. If I remember correctly the melonized gear had a faint purple hue to it and the other was dull black.
I remember looking at the melonized gear and the standard gear in bright sunlight. If I remember correctly the melonized gear had a faint purple hue to it and the other was dull black.
